Stitch-forming mechanism for sewing machines



May 8, 1923.

E. B. ALLEN STITCH FORMING MECHANISM FOR SEWING MACHINES Filed Feb. 18,1922 \WENTOR ATTORNEY WITNESSES: v

Patented May 8, 1923.

FACTURING COMPANY, or JERSEY. a

STITCH-FORMING MECHANISM Fen SEWING-'MAGHINES. v

Application filed February 18,1922. Serial No. 537,382.

To aZZwZzom it'mag concern."

Be it known that I, EDWARD B. ALLEN, a citizen of the United States,residing at Newtown, in the county of F airfield and State ofConnecticut, have invented certain new and useful Improvements inStitch-Forming l\/Iechanisms for Sewing Machines, of which the followingis a specification, reference being had therein to the accompanyingdrawings.

This invention relates to overseaming stitch-forming mechanism moreparticularly of the type disclosed in the patent to Allen et al., N o.1,372,st73, March 22, 1 921,

and adapted for buttonhole sewing. The

invention has for an object to provide the stitch-forming mechanism withmeans facilitating the setting of the purl close to the edge of the seamor, when sewing buttonholes, close to' the buttonhole slit. I

In stitch-forming mechanism of thecharacter under consideration, theconcatenation of-the looper-thread with the needle-loops forms the purland, in accordance with the present improvement a device is interposedbetween the looper and the "work for holding the looper-thread leadingfrom the looper to the last stitch in'an elevated or more nearlyhorizontal position than heretofore, so that when the looper isretracted. to tighten the looper-loop, such loop willbe set over closeto the buttonhole-slit without straining or-distending the previousneedle loop. The purl or line of the interlocked needle andlooper-threadloops willthus' be set over close to the buttonhole-slit.'

In the accompanying drawings, Fig. lis a front elevation ofstitch-forming devices embodying the present improvement. Fig. 2 is aleft side elevation of the same. Fig. 3 is a right side elevation of oneof the loop detaining elements shown in Figs. 1 and 2 and Fig. 4 is afragmentary View similar to Fig.2 but at a later stage in thestitch-forming cycle.

In the specific embodiment of the invention chosen for the purposes ofthe presentdisclosure 1 represents the reciprocating and laterallyjogging needle of the well known type disclosed in said Allen et al..patent. The needle 1 is so actuated as to pass alternately through thebuttonhole-slit 2 in the Work 3 and at a distance from such slit. Thework 3 is held clamped by the lower worksupporting plates '4: and upperclamping feet 5 of a suitable machine such as that dis closed in myPatent No. 1,372,472, of March 22, 1921'.

EDWARD B; A-IlLENyOF NEWTOWN, oom acrrounnssrenon r'o rr-IE srnennmanu-ELIZABETH, new JERSEY, A oonronarron or nnw- Cooperating with the needle1 are the i I lower looping devices which aremounted on the usual turret6 and comprise theithreaded-looper 7, non-threaded looper v8, and loop'fdetainers 9 and 10. The loopers 7 and 8are carried by the arms 11 andpost 14 rising from-the turret 6; The loop} The turret carries the.usual needle-throat or button 16.

12 of arocking looper-carrier which is pivotedat 13 to the Referring to,ig. 1 it will be observed that the needle 1 having in the ine'antimebeen advanced from,

dotted line position, Fig; 2, tofull' line or loop-seizing position. Thelooper-thread 19" leads downwardly from the workjto the threaded looper7 and, during the retraction of the looper Ttothe position shown injFig.

1, a pull is exerted on the looper-thread. 'Heretofo re thispull wasexerted in-a direction from the last'stitch straightto' theeye of thethreaded looper, and such direction p is rising from-its:depthstitch Ydescent; ts loop 17 havmgbeen seized and was inclined at an angle of 45or moreto the plane of'th'e work, making'fit diflicult to set up theconcatenated loops without disturbing or dis-tendingthe loops previouslyset up.

In accordance with the present improve-- ment provislon is madefor'supporting the looper-thread between the looper and the work, sothat the looperethread length adjacent the last stitch will extend awayfrom the buttonhole-slitin a more-nearly liorie zontal direction thanheretofore, whereby the pull on the vlooper-threadwill have a largelateral component and an insignificant.

vertical component. By so supporting the looper-thread, the purl may beeffectively pulled over to the buttonhole-slit and a uttonhole ofsatisfactory-appearance produced even though the looper oscillates abouta horizontal axis as iscustomary in turretmachines.

The means for supporting the looperthread may conveniently be made up inthe form of a horn 2O rigid with or secured to the loop-detainer 9 andhaving a downturned point 21 projecting forwardly beyond and over thehorn 18, so as to pass below the looper-thread 19 and lift the lattertoward the work 3. The horn also serves to separate the looper-threadfrom the needle-loop 17 and hold the looper-thread 19 clear of the horn18 so that as the horn 18 advances to seize the needle-loop 17 it willnot catch the looper-thread. On the slit-stitch descent of the needle,Fig. 4;, it passes in front of the looper-thread 19 and into theneedle-loop 17 which is held spread by the horn 18 of the loop-detainer9.

The invention is not to be understood as limited to the form andarrangement of parts shown and described as it is believed to be broadlynew to provide means cooperating with the threaded-looper of anoverseaming stitch-forming mechanism to bend the looper-thread betweenthe looper and the last stitch andthereby facilitate the setting of theurl close to the edge of the work;

aving thus set forth the nature of the invention, what I claim hereinis 1. In overs'eaming stitch-forming mechanism, the combination withneedle and looper devices for concatenating needle and looper threads toform a purl stitch, of means for bending toward the plane of the workthe length of looper-thread between the looper and the last stitch,thereby facilitating'the setting of the purl close to the edge of theseam. a

2. In overseaming stitch-forming mechanism, the combination with needlemechanism and looper mechanism including threaded and non-threadedloopers operating alternately about substantially horizontal axes toseize needle-loops, of means for bending the length of looper-threadbetween the threaded loope'r and the last stitch toward the plane of thework while the non-thread- 4C. Overseaming stitch-forming mechanismcomprising, needle mechanism operating to pass depth-stitch andslit-stitch needle-loops alternately through the work, threaded andnon-threaded loopers operating alternately to seize such loops, and aloop-detainer having a horn for seizing the depth-stitch needle-loop onthe non-threaded looper, said detainer having a second horn disposedabove and projecting forwardly of said first mentioned horn and adaptedto separate the looper-thread from the depth-stitch needle-loop. i

5. O'vei'seaming stitch-forming mechanism comprising, needle mechanismoperating to pass depthand slit-stitch needleloops alternately throughthe work in different paths, a threaded looper for seizing theslit-stitch needle-loop, a non-threaded looper for seizing thedepth-stitch needleloop and a pair of loop-detainers for seizing theloops from their respective loopers and positioning them unassistedbysaidloopers for entry by the needle, the loop-detainer whichcooperates with the non-threaded looper being formed with a loop-seizinghorn and with a looper-thread deflecting'horn overhanging theloop-seizing horn.

In testimonywhereof, I have signed my name to this specification.

EDWARD B. ALLEN.

